Some generic names, such as snapper, may refer to a variety of fish. Other names, like Chilean sea bass are a more palatable name for a fish that is actually named something else. The FDA maintains a list of acceptable names and the corresponding actual fish that may be sold under the name.

This slideshow runs through the common names you see on the menu and what the fish actually is, or might be. Again, these are acceptable names and the fish being sold under the name is approved by the FDA.

We'll start with Perch, a very popular choice at many restaurants.

Perch can be of several different varieties, including Pacific Ocean Perch, shown here, and Golden Redfish. Each fish can legitimately be sold under the name Perch. There is also a freshwater variety of Perch.

Haddock is also another common choice.

Haddock is what it sounds like -- Haddock. It's part of the Cod family.

Chilean Sea Bass is a different story.

Chilean Sea Bass is actually something known as the Patagonian Toothfish. The real name isn't quite as appetizing.

Orange Roughy is what it sounds like -- Orange Roughy.

This is what Orange Roughy looks like before it gets to the restaurant.